Lactic Acid Bacteria
Lactobacillus acidophilus The bacterium is a member of the normal flora of humans, found in the oral cavity, the small intestine, and the vaginal epithelium, where it is thought to play a beneficial role. The organism is generally the first bacterium listed as present in probiotic concoctions.more...
Lactococcus lactis exhibits virtually all of the foregoing characteristics and applications of a lactic acid bacterium. This bacterium is chosen because of its preeminence in cheese making and its status as the natural nominee as the state microbe of the dairy state of Wisconsin.more...
Lactococcus lactis. UW Department of Bacteriology strain LcL325UW.Magnification 20000X. Scanning electron micrograph by Joseph A. Heintz, University of Wisconsin-Madison.
Lactococcus lactis is a microbe classified informally as a Lactic Acid Bacterium because it ferments milk sugar (lactose) to lactic acid. Lactococci are typically spherical or ovoid cells, about 1.2µm by 1.5µm, occurring in pairs and short chains. They are Gram-positive, non motile, and do not form spores. Lactococci are found associated with plant material, mainly grasses, from which they are easily inoculated into milk. Hence, they are found normally in milk and may be a natural cause of souring. Lactococcus lactis has two subspecies, lactis and cremoris, both of which are essential in manufacture of many varieties of cheese and other fermented milk products.